Information processing by the skin senses (primarily tactile systems) may be utilized when the effectiveness of conventional channel is limited, as in high noise environments, when existing channels are overtaxed, as in jet and space control systems, or when existing channels suffer a deficit, as in the sensory losses of deafness and blindness. Of increasing interest are the sensory characteristics associated with advancing age and in pathologies that may affect neural functioning. Before these needs may be satisfied, sizeable gaps must be filled in our knowledge of the basic functioning of the cutaneous sensory systems. The aim of the proposed experiments is to extend our understanding of the psychophysical characteristics of the responses to vibrotactile stimulation in humans. The experiments fall into four general problem areas: (1) spatiotemporal aspects of vibrotactile sensation, (2) sensory interactions among cutaneous mechanoreceptor systems, (3) interactions between vibrotaction and other sense modalities (cutaneous and non-cutaneous), and (4) characteristics of cutaneous sensory systems as a function of age and sex.